Something's cooking in Barcelona. The city that has long been Spain's stockpot of style is boiling over with creative fervor—whether it's on a restaurant stove or in artists' studios, design ateliers, or just out on the streets. Ferran Adrià, the high priest of nueva cocina, adores his hometown: "The best thing about Barcelona is that it has absolutely everything you could ask for in a big cosmopolitan modern city," the chef says, "but it can still be navigated as easily as a charming medieval one." Like the perfect mise en place of a professional kitchen, Barcelona has every ingredient prepared exactly as it should be and it's all within easy reach.

There are few cities in the world in which a 20-minute stroll might take you from a 13th-century Gothic cathedral, past a museum full of Picassos, to a world-famous opera house, and then onto a sandy beach and into the azure waters of the Mediterranean. National Geographic recently named Barcelona the best beach city in the world, which—given that cities like Rio de Janeiro were in the running—is not bad for a place that pretty much forgot it even had a beach for several hundred years.

It was not until hosting the 1992 Olympics that Barcelona rediscovered its coastline—then virtually inaccessible behind old railroad tracks, dockyards, and warehouses—and since then it's been investing heavily to open it all back up. But with tourism booming in the years since the Summer Games, some of the city's coolest neighborhoods were on the verge of becoming theme parks.

"I can really feel that the city is in the process of reinventing itself," says Santi Moix, a painter who divides his time between Barcelona and New York. "There is a return to authenticity and quality not just in arts, but in everything. Now that we've shown the world what we can do with food there is this incredible energy to do the same in other arenas."

An arena in which the city already excels is hospitality, with something like 20 five-star hotels—including the swank W and Mandarin Oriental. And no hotel seems complete without a Michelin-starred restaurant. Moix's favorite is Drolma, inside the Hotel Majestic, where chef Fermí Puig serves his updated Catalan classics in grand style.

One imagines the accommodations were more rustic when the Carthaginians first set up shop here in the third century B.C. Today's Barcelona of just over 1.6 million people is the capital of Spain's northeastern Catalunya region, but it was already a thriving cosmopolitan port back when landlocked Madrid was just a dusty fortress with some houses clustered around it.

Through periods of tremendous prosperity or during invasions, wars, and devastating plagues, Catalans' enduring merchant mentality has always meant getting back to business without missing a beat. By the mid-19th century, the walled city—the area today known as the Gothic Quarter—was among the most densely populated in the world. When the walls came down in the 1850s, Barcelona spread out, in surprisingly orderly fashion, to the Eixample, a vast grid of streets and avenues that remains a model of intelligent urban planning.

The Eixample's streets are home to some of the most beloved buildings in the world: Modernista (as Art Nouveau is known in Spanish) marvels such as Casa Milà and Casa Batlló by Antoni Gaudí and other striking examples by his contemporaries, such as Lluís Domènech i Montaner and Josep Puig i Cadafalch, who have left an indelible imprint on the look of the city. "Barcelona has long been an architect's city," says Oscar Tusquets Blanca, who designed the sensitive expansion and modernization of Domènech i Montaner's ornate music hall, the Palau de la Música Catalana. "Styles, movements, and revivals last as long as they last," Tusquets Blanca explains. "Tremendous creativity was unleashed by the Russian Revolution, for instance, but that lasted about five years. For some reason, Barcelona's creative run has been considerably longer."

Certainly the city's architectural "run" began long before Art Nouveau. The best way to understand its history is to trace development from neighborhood to neighborhood, starting in the Gothic Quarter, which faces the port and is the heart of the old city. Here, in a jumble of narrow streets lined with 400-, 500-, and 600-year-old houses that appear to be holding one another up, you'll find the Cathedral, City Hall, and countless Gothic and Renaissance palaces with their brooding portals opening onto charming interior courtyards.

At the old town's eastern edge are the Born and Ribera neighborhoods, now a vortex of trendsetting shops. As laundry flutters on the balconies above, a different kind of rag trade unfolds in boutiques like La Comercial, which has five outposts in the space of two blocks. Among artist Santi Moix's mandatory stops in the Born is Vila Viniteca, a wine and specialty food shop run by Joaquim Vila, who Moix says "can tell you everything you need to know about Spanish and Catalan wines."

To the west of the old city is the barrio known as El Raval, which, though rapidly gentrifying, still mixes in enough urban grit to give it an authentic edge (translation: keep a tight grip on your wallet or purse). The main boulevard of the old city, the bustling Rambla, runs from the Plaça de Catalunya down to the old port. There is a lot to love about the Rambla, despite its exotic-bird sellers and unruly hubbub. There's the famous Boqueria market, an 18th-century produce market that is the heart and soul of the city's culinary circuit. (It says everything that two of Barcelona's biggest tourist attractions are produce markets—the other, the Santa Caterina market in La Ribera, has a wildly undulating mosaic-clad roof and was featured in an architecture exhibition at the Museum of Modern Art in New York.) Other addresses worth noting are the Gran Teatre del Liceu, one of Europe's most storied opera houses, and MACBA, the museum of contemporary art built by Richard Meier.

Beyond its flamboyant architecture, the other notable draw of the Eixample is its shopping. The famous Passeig de Gràcia is lined with luxury boutiques such as Bagués-Masriera in Puig i Cadafalch's neo-Gothic Casa Amatller. Besides their own contemporary designs, Bagués continues to produce (from the original molds) the stunning gold and enamel jewelry designs of Lluís Masriera, one of the masters of Art Nouveau.

Just steps away from such high-end emporia, on the side streets of the Eixample, a handful of independent local fashion designers are at work. "Barcelona has this incredible heritage of design and craft, and you can still find talented people producing amazing clothes and leather goods right here in the city," says Lisa Richardson, a former fashion designer in Milan. Two years ago she and fellow fashionista Niki Robinson started Antiques & Boutiques, offering clients bespoke shopping tours throughout the city.

An entirely different retail atmosphere exists north of the broad Avinguda Diagonal in the multiethnic and arty neighborhood of Gràcia. Once a separate village that gave the Passeig de Gràcia (essentially the road to Gràcia) its name, the area still maintains its own distinct flavor and village atmosphere. With narrower streets, smaller buildings, and lower rents than the surrounding Eixample, Gràcia is a haven for retail upstarts, with lots of trendy shops selling sneakers, bikes, and vintage clothing; it also offers wine bars and a fantastic selection of Moroccan, Portuguese, Greek, and Lebanese restaurants.

Where Gràcia converges with the Eixample, tiny Carrer Sèneca is dense with cool shops—featuring everything from designer baby clothes to vintage purses—as well as restaurants that mix high style with easygoing charm. You can even stay in the neighborhood at Casa Fuster, one of Domènech i Montaner's most sumptuous residential structures and now a five-star hotel with a famous jazz bar, Café Vienés, where Woody Allen jammed while shooting Vicky Cristina Barcelona.

A few 21st-century architectural marvels have already risen in the city—or at least at its edges. Toyo Ito, Richard Rogers, and Jean Nou­vel have all built shimmering towers. And of course the spires of Gaudí's Sagrada Família—recently consecrated by the Pope—continue their ascent on the horizon. It is now slated for completion in 2026, and despite the fact that it's being constructed without Gaudí (or any of his drawings, which were lost decades ago), it will still be considered the most important religious structure of the 20th century.

Gastronomically the city is thriving, as many alums from El Bulli, Ferran Adrià's world-famous restaurant an hour north of Barcelona (which is scheduled to close at least temporarily next year), have set up their own establishments. El Bulli's former executive chef, Albert Raurich, has opened the Asian-inspired Dos Palillos in the funky Casa Camper Hotel in the Raval. And Carles Abellán is now in charge of five kitchens, including the low-key Tapas 24 as well as the swank grill Bravo at the W hotel. Even as he contemplates his next move, Adrià and his brother have just launched a tapas bar called Tickets, in the heart of the theater district, which will no doubt be the next hot ticket in town.

But then revivals and beginnings are nothing new in a city where locals still dance the Sardana in front of the Cathedral on Sundays and vintage jewelry is snapped up by urban hipsters at the weekend antiques market near the port. In Barcelona, gorgeous authenticity lurks around every corner.

Sing the praises of Modernista. The great Modernista (Spanish Art Nouveau) architect Lluís Domènech i Montaner is at his best with his ornate Palau de la Música Catalana (Palau de la Música 4-6, 90-244-2882; palaumusica.org).

Go Gothic. Even before the surrounding Born neighborhood became trendy, the locals preferred Santa María del Mar (Plaça de Santa María del Mar, 93-310-2390), a 14th-century parish church, to the big and brooding Cathedral.

Hit the beach. One of this bustling city's greatest charms is its proximity to the sea and the abundance of sun and sand.

Museu del Modernisme Catala, Carrer de Balmes 48, 93-272-2896; mmcat.cat: A fabulous new museum specializing in the art and decoration of the Modernista period, with works by such talents as Casas, Gaudí, and Homar.

Museu Picasso, Carrer de Montcada 15-23, 93-256-3000; museupicasso.bcn.es: Trace Picasso's transformation from gifted teenager to brilliant modern master through this selection of mostly early works, many created during his years in Barcelona.

WHERE TO STAY

Hotel Casa Fuster, Passeig de Gràcia 132, 93-255-3000; hotelescenter.com: A five-star hotel, with an inviting rooftop pool, deftly inserted into a Modernista wonder built by the influential architect Lluís Domènech i Montaner.

Mandarin Oriental, Passeig de Gràcia 38-40, 93-151-8888; mandarinoriental.com: Ultrachic modern luxury in rooms designed by Patricia Urquiola and a prime location close to uptown shops and old-town monuments.

Hotel Omm, Carrer del Rosselló 265, 93-445-4000; hotelomm.es: Steps from Gaudí's Casa Milà, Omm offers some of the most spacious rooms in the city, as well as a spa and nightclub.

W Barcelona, Plaça de la Rosa dels Vents 1, 93-295-2800; w-barcelona.com: Architect Ricardo Bofill gave the city a new icon, and it's hard to beat the beachfront locale for a summer stay.

Casa Paloma, Carrer de Casanova 209, 93-200-8296; casapalomabcn.com: A new and rapidly rising hot spot for excellent steaks in a clubby atmosphere.

Dos Cielos, Diagonal Pere IV 272-286, 93-367-2070; doscielos.com: With an emphasis on vegetables, the Torres brothers serve up haute cuisine as airy as the views from the restaurant's stunning 24th-story perch.